The present invention relates to the use of saponins to inhibit cholesterol absorption. More particularly, the present invention relates to the enhancement of the cholesterol combining properties of saponins, by acid hydrolysis of the saponins under mild conditions.
Saponins from plant sources such as alfalfa have been known to have a variety of biological effects upon various animals. Included among the chemical activities of certain saponins is the ability to form chemical complexes with sterols, including cholesterol. Such activities are described, for example, in the following publications: Proc. Soc. Exp. Biol. Med., 99, 424 (1958); Poultry Sci., 37, 42 (1958); Poultry Sci., 51, 677, (1972); J. Lipid Res., 12, 482 (1971); and J. Sci. Food Agric., 27 (1), 63-72 (1976).
The addition of certain saponins to the diets of some animal has been found to prevent hypercholesterolemia. By the present invention, it has been found that the ability of saponins to prevent hypercholesterolemia may be enhanced at least about five fold by prior treatment of the saponins with acid. Thus the method of the present invention enhances the ability of saponins to inhibit cholesterol absorption and to alleviate hypercholesterolemia. The present method includes mild acid treatment of the saponins. The treated saponins may then be advantageously employed by oral administration to patients with hypercholesterolemia.